Struggling with this and it seems that it should be so easy, but how do I make this gnomes hands and fingers shorter and fatter?

Is this the same gnome you imported from Poser? I think you would have a easier time using the dials in poser to get a more even distribution of making them shorter and fatter. In Blender selecting them object then going into edit mode you can use the scaling tool just not sure the results would be favorable. 

ALT- S will fatten/shrink the selected polys.

Also you could use the inflate brush in the sculpting tools. Infact you could use several of the sculpting tools to tweak the hand.

Yes, Lobo3433, it is the same gnome. And yes, I tried manipulating the hand in Poser but the hand and fingers got weird. Doesn't seem to be much flexibility in the Poser morphs.

I'll try the inflate brush and other sculpting tools that Cybermonk has recommended. I'll let you know how it turns out.

Thank you!

For some reason I can't get sculpt to work, not even on a cube. I go to Sculpt Mode, select the brush and paint away on the cube but nothing happens. Do I need to set up something?

That cube has 1 polygon to a side. That is not much definition to sculpt with. The reason you ar not having any effect is your brush is probably painting inside a big polygon like inthe picture. Hit the F KEY to resize your brush so it will hit he verts in the corners.  or better yet subdivide the cube so you have something to work with.

depending on what you are trying to sculpt you neeed to add topology to the mesh

in the 2.66 series and after there is a tool called dynamic topology in the sculpt menu on the left

go to sculpt mode and enable dynamic topology under the toplogy tab

you will see a button titled enable dynamic

that will tessalate the mesh only where you tell it to sculpt at

or you could use a subdivision surface modifier

Quote - depending on what you are trying to sculpt you neeed to add topology to the mesh

in the 2.66 series and after there is a tool called dynamic topology in the sculpt menu on the left

go to sculpt mode and enable dynamic topology under the toplogy tab

you will see a button titled enable dynamic

that will tessalate the mesh only where you tell it to sculpt at

or you could use a subdivision surface modifier

 

Do NOT use dynamic topology if the mesh you're sculpting has UV maps on it already, I'm almost certain it will hose your UVs. I don't have time to test it right now, but generally that kind of change to the geometry is game over for any UV maps you have. The Subidivision Modifier I believe works with UVs, and the "Multiresolution" Modifier I know does, the latter being the most common modifier for sculpting.

that would be the reason i did post it as depending on

dynamic will 1000000% kill any mapping that was done it is used as an initial sculpt tool that can be retopo'd later

the subdidvision is designed to work with the mapsbut can be a bit hinky at times if you go too far with the sculpting

you could add loop cuts manualy without effecting the maps too much

but for general sculpting the base mesh needs added geometry if you use a simple primitive